Re: [patch v2] x86: reduce srat verbosity in the kernel log

From: Yinghai Lu
Date: Tue Nov 10 2009 - 16:44:47 EST


Ingo Molnar wrote:
> * David Rientjes <rientjes@xxxxxxxxxx> wrote:
>
>> On Tue, 27 Oct 2009, David Rientjes wrote:
>>
>>> x86: reduce srat verbosity in the kernel log
>>>
>>> It's possible to reduce the number of SRAT messages emitted to the kernel
>>> log by printing each valid pxm once and then creating bitmaps to represent
>>> the apic ids that map to the same node.
>>>
>>> This reduces lines such as
>>>
>>> SRAT: PXM 0 -> APIC 0 -> Node 0
>>> SRAT: PXM 0 -> APIC 1 -> Node 0
>>> SRAT: PXM 1 -> APIC 2 -> Node 1
>>> SRAT: PXM 1 -> APIC 3 -> Node 1
>>>
>>> to
>>>
>>> SRAT: PXM 0 -> APIC {0-1} -> Node 0
>>> SRAT: PXM 1 -> APIC {2-3} -> Node 1
>>>
>>> The buffer used to store the apic id list is 128 characters in length.
>>> If that is too small to represent all the apic id ranges that are bound
>>> to a single pxm, a trailing "..." is added. APICID_LIST_LEN should be
>>> manually increased for such configurations.
>>>
>>> Acked-by: Mike Travis <travis@xxxxxxx>
>>> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
>> Ingo, have you had a chance to look at merging this yet?
>
> I'm waiting for Mike to test them (and other patches) and send a new
> series out with bits to pick up.
>
> But i really dont like such type of buffering - in the past they tended
> to be problematic. Why print this info at all in the default bootup?
> It's not needed on a correctly functioning system.
>
> For failure analysis make it opt-in available via a boot parameter (if
> it's needed for bootup analysis) - but otherwise just dont print it.
>
make them to depend on apic=debug or apic=verbose?

YH
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/